Wow, picking an airplane around an engine. That's a different approach. The K&B 40 is not a weak engine despite not being schnurle ported. You should be able to run any 40 sized aircraft with no problems. I have one on a profile funfly plane, and it is a kick to use at just half throttle. We used to use them for flying Q500 racing planes like the Preditor from Lanier. You can get close to 100 mph with a good light one.

Dan